Objective: To study the structure basis of immunological specificities of various glycolipids, the metabolic activities, and the organization of glycolipids in normal and tumor cell surfaces. Approach: The chemical structure and immunological properties of surface-exposed glycolipids and glycoproteins in normal and tumor cell membranes will be studied with particular emphasis on isolation and characterization of ceramide tetrasaccharide with a specific surface label. Chemical and immunological characterization of galactosyl protein A, which is present on normal cell surface and deleted completely in transformed cell, will be chemically identified. Further studies of glycolipid synthesis and degradation in relation to cell contact, cell proliferation, cell cycle, and mechanism of such control in tumor cell surface, is also a major part of the work. Tumorigenic and metastatic properties of membrane glycolipids and glycoproteins will be compared with various cells with different malignancy.